1. Field of the Invention
The present invention relates to pipe cleaning, and more specifically pipe cleaning with a gas stream.
2. Description of Related Art including Information Disclosed under 37 CFR 1.97 and 37 CFR 1.98.
Transport pipes (especially liquid transport pipes) are known to become infested with many forms of build up, including tubercles in a case of municipal water pipes. The pipes become sclerotic and continually narrow as tubercles build up. Regardless of pipe type (gas/liquid/solid transport), flow eventually occludes with tubercle residue and other build up. Few viable industrial and commercial solutions are available to deal with sclerotic pipes quickly and effectively.
One option is to replace infected pipes, but this is frequently unnecessary, time consuming, impractical in urban areas and established neighborhoods, expensive, and results in an additional problem of waste pipe disposal.
Another option is to accelerate abrasive projectiles (like rocks of progressive caliber) through infected pipes. A pipe is pressurized with a gas stream, and abrasive projectiles are fed into the stream. The streaming projectiles strike and break away protruding tubercle portions, and discharge out of the pipe along with broken tubercles. This option's defects include inability to clean a) smaller tubercle portions and thin residual layers satisfactorily; and b) pipe elbows, bends, and pipe joints satisfactorily. This option does not always leave a properly prepared and dried finish for bonding, making subsequent coating or lining difficult and unsatisfactory.
Certain pipes, over time, can build up corrosion or retain remnants of previous coatings (bitumen, cement), and the like. Normally these patches cannot be fully removed without harsh and corrosive chemicals. Projectile cleaning alone is insufficient to completely remove these remnants.
Other defects exist in the prior art, and are also discussed in U.S. patent application Ser. No. 12/923,201.